The present invention relates to a surveying device and a surveying system when a surveying operation is performed by a single surveying operator or by cooperation of two or more surveying operators.
In a surveying operation performed in a civil engineering work, e.g. a surveying operation in a road construction, a measurement is performed on positions on both sides of the road, on a difference in elevation, on a width of the road, etc., and a plurality of measuring points are measured at the same time. As a result, the surveying operation is a cooperative operation to be performed by two or more surveying operators.
A surveying device, by which measurement can be made on a plurality of measuring points at the same time, is disclosed in JP-A-2006-337302.
In a surveying device according to JP-A-2006-337302, laser beams for forming reference plane including three or more fan-shaped laser beams, with at least one of the laser beams being tilted, are projected in rotary irradiation, and the reference plane is formed. Further, an elevation angle is measured according to a time difference when a photodetection unit of a side of an object to be measured receives a plurality of fan-shaped laser beams. Also, by receiving a reflected laser beam from the object to be measured, a horizontal angle is measured from a projecting direction of the fan-shaped laser beam at the moment when the reflected laser beam is received. Further, the surveying device projects a distance measuring light, which are spread in vertical direction, in rotary irradiation. Then, the reflected distance measuring light from the object to be measured is received, and an electro-optical distance measurement is performed on a distance to the object to be measured. A position in vertical direction of the object to be measured is calculated based on an elevation angle and the measured distance, and a three-dimensional position of the object to be measured is measured.
By the surveying device as described above, measurement can be performed at the same time on a plurality of objects to be measured (hereinafter referred as “multi-measurement), which are present within a projecting range of the fan-shaped laser beam and of the distance measuring light, by projecting the fan-shaped laser beams and the distance measuring light spread in vertical direction in rotary irradiation, i.e. on a plurality of objects to be measured which are present within total circumference in horizontal direction and within the range of spreading in vertical direction of these two types of laser beams.
By the surveying device as described above, the distance measuring light spread in vertical direction are projected in rotary irradiation. Then, the reflected light from the objects to be measured are received, and the electro-optical distance measurement is performed. As a result, an optical intensity of each of the distance measuring light is decreased, and influence of noise light becomes stronger, and this leads to lower measurement accuracy. Further, because the distance measuring light is rotated at high velocity, a measuring time of one measurement is short. Also, there are not many distance measurement data to be averaged, and it is not possible to improve the measurement accuracy. For the purpose of improving the measurement accuracy, the light must be projected in rotary irradiation many times, longer time is required for the measurement, and a working efficiency is decreased.
Further, because the distance measuring light is spread in vertical direction, an optical intensity of the received light is decreased more when the distance to be measured is longer. Thus, these are a problem that the distance which can be measured is lengthen, and other problems.
A total station is known as a means, by which measurement can be made to a measuring point with higher accuracy. The total station has a tracking function. For instance, similarly to the case of design-based surveying operation, a surveying operator moves an object to be measured (prism) to each of the measuring points. The total station tracks each object to be measured and performs the measurement on each of the measuring points.
The total station with tracking function can be operated by one operator (one-man operated measurement). The measurement can be made with high accuracy and a working efficiency of the measurement is also high, but it is not possible to perform measurements at a multiple points at the same time. As a result, in case it is necessary to perform measurements on a multiple points at the same time, the working efficiency is extremely decreased.
JP-A-2004-212058 discloses a method, by which two or more fan-shaped laser beams, with at least one fan-shaped laser beam being tilted, are projected in rotary irradiation, a horizontal reference plane is formed, and an elevation angle with respect to the horizontal reference plane is determined from a tilt angle of the tilted fan-shaped laser beam.